Reactive furnace device. Do-it-yourself long-burning rocket stove. Carrying out a furnace test

19.11.2019

What are the designs of furnaces long burning? From this article, you will learn how vertically loaded long-burning furnaces are fundamentally different and how to increase their efficiency. We will tell you about the secrets of their manufacture and give step-by-step instructions.

Continuing the theme of manufacturing and improving long-burning furnaces (PDF), we will describe in detail devices with vertical loading. The advantages of this option:

Compact combustion chamber.
The use of gravity at work.
More efficient sale of fuel (firewood).
Low temperature ejection - no need to heavily insulate the chimney.
Relative cleanliness (smoke-free) emission - fewer problems with neighbors.

The fundamental difference between such stoves and potbelly stoves and their derivatives is the gradual combustion of fuel and, as a result, a smooth and uniform distribution of heat (in stoves, the entire load flares up at once).

The two most popular types of PDGs are Bubafonya and Raketa (rocket furnace). In the first case, energy is realized from the combustion of wood under pressure with an oxygen deficiency, in the second, a reactive process that occurs during a temperature difference.

"Bubafonya" or piston PDG

This stove got its original name from the nickname of the author, who first posted the scheme to the public. Whether he is the inventor of this variety is unknown. Most likely, in one form or another, it has existed since ancient times, since its action is based only on the laws of physics and nature.

The peculiarity of this variant of the PDG is the constant pressure of the piston, the heel of which balances and maintains a constant uniform temperature, preventing individual sections from cooling or overheating.

Design

"Bubafonya" is something like a piston engine cylinder in an extremely primitive form:

Combustion chamber (CC). An open cylindrical container (barrel, cylinder, pipe) without hatches and with a chimney at the upper boundary. The size of the COP can range from 20 to 240 liters.
Piston. Steel pipe with a section of 75 mm with a round heel at one end. The heel has a diameter of 40-50 mm less than the KS, and a hole for the diameter of the pipe. In the outer part of the heel has ribs to admit air to the combustion area. Functionally, this part plays the role of an air duct and a press.
Lid. Plain steel cover with a hole for the duct pipe.

The simplicity and reliability of the design, as well as the availability of material, made this stove the most popular among villagers and garage owners. "Bubafonya" is the record holder for the duration of burning - CS from a 200 l barrel with a full dense vertical load works 20-24 hours.

How to assemble

1. Cut off the top cover of the barrel (should not be rotten). It can be used later under the oven lid. If this gas bottle, cut off along the border of the soldering of the head and wall. At 20-30 mm from the upper edge, we cut out the chimney hole and weld the channel from the pipe 100-120 mm.

2. Air duct (BB). For CS of any size, a sufficient internal diameter of the explosive pipe is 75 mm. The length of the explosive is equal to the height of the CS plus 200-300 mm.

3. Heel. A sheet of 4-6 mm is cut out in the form of a circle with a diameter smaller than the combustion chamber by 30-40 mm.

4. Cut a hole in the center of the heel equal to the inner diameter of the explosive plus 2-3 mm. Along the edge, you can weld a side from a strip for piston stability when the firebox is loaded.

5. We weld corners 30x30 or 40x40 on the working surface of the heel in the form of rays from the center.

6. We weld the explosive to the heel at an angle of strictly 90º on the back side of the ribs.

7. At the free end of the explosive, we weld the M6 nut from the inside. We cut the damper along the section of the explosive and install it on the screw. You can use a magnet of a suitable diameter. This damper regulates the air supply to the combustion chamber.

8. On the lid we weld a strip of 20-30 mm around the circumference like a side.

Making the most of it

Convector. To remove heat from the CS (furnace) there is a simple and effective solution based on air convection.

Convection is a type of heat transfer in which heat energy is transferred in streams or jets.

For the device of a primitive convector, we need a profiled galvanized sheet with a medium wave, which you just need to wrap around the combustion chamber. The profile waves will serve as channels through which the air will pass. Heated from the furnace, he will rush up, and his place will be taken by cold air coming from the bottom of the channel. If there is no profiled sheet, you can fasten CD or UD profile trimmings around the firebox and chimney.

Casing. Another type of convector can be a primitive coaxial system.

Coaxial - from Latin co- joint and axis- axis, i.e. having a common axis.

To do this, we weld brackets 40-50 mm long onto the combustion chamber, retreating 50 mm from the top and bottom. We fix a sheet of metal on them. The thickness here is not of decisive importance, since air acts as a coolant, and the casing itself will not heat up. Suitable thin galvanized, which can be made removable.

Long straight chimney. If it is possible to easily increase the length of the chimney inside the room, this will allow you to remove the remaining temperature of the exhaust gases.

Fan, directed to the PDG, effectively mixes the air, which will give a quick and uniform heating of the room.

The described version of the furnace has one, but a significant drawback, which can be considered as a tribute to the simplicity of the design. Cleaning the ash pan is a dusty job. The bottom part of the CS serves as the ash pan itself, and the extraction of ash through the side is inconvenient, but necessary.

Another nuance can only be called “production costs”. When using a barrel, the walls of the firebox burn out relatively quickly. With intensive use (at high temperatures), the combustion chamber will have to be replaced after 3-4 seasons. But here, too, simplicity ensures success - it is enough to find the same barrel. The gas cylinder in this case will serve for decades.

"Rocket" or jet furnace (RP)

Another type of energy efficient stove is known as the "Rocket" or "Rocket stove". She received a sonorous name because of the jet process based on heat transfer with a significant temperature difference (and the resulting thrust), which is also implemented in rocket jet engines. This natural phenomenon is inscribed in the basic laws of physics due to its trouble-free operation.

Design

RP always has a “knee” of no more than 90 ° in one form or another. That is, the chimney is located at a right or acute angle to the bottom of the furnace. It is obligatory to have an air duct (BB), which is often located adjacent (through the wall) to the firebox.

Working principle and advantages

The main difference between the RP and the previously described furnaces is that the temperature is concentrated not in the furnace, but in the air flow, which is in constant dynamics. The continuous draft that occurs at the place of heating (elbow) brings oxygen with the combustion air flow into the furnace through the explosive, in the furnace the air receives thermal energy from fuel combustion and gives it away at the place of temperature difference (knee and “surroundings”), due to which the thrust is maintained.

In the constant RP mode, air supply adjustment is not required - the natural desire for a balance of processes provides draft of exactly the same force as is required to realize the temperature in the furnace. The exit of exhaust gases also passes naturally - by the pressure of heated air (therefore, the RP does not require a high chimney pipe).

Reactivity effect heat flow we will implement in stages, more and more complicating the design.

Stage one. Stream in its purest form

As we have already found out, the main element and condition for the existence of the flow is the elbow of the channel. By welding at an angle of 90 ° two pipes with a diameter of 150 mm or more, correlating as 1/2, we will get a finished “rocket” firebox with a chimney pipe. The short section is horizontal, the long section is vertical. If you make a fire in a horizontal, the flame will go out through a vertical pipe.

A primitive version of the secondary air supply can be organized by installing a metal sheet on the brackets inside the furnace - the hearth will be separated from the air duct. In this case, the air passing through it will fall into the corner of the knee, which allows us to call it secondary. You can weld legs to such a device and put a grate for a frying pan on the upper channel.

Stage two. "Rocket potbelly stove"

We take the construction described above as a basis, and add one more element - a horizontal section (channel). The rectangular section of the channels will be more convenient to use than pipes.

Rocket potbelly stove: 1 - plate; 2 - area of heating and heat exchange; 3 - air flow

The air duct in this case can be located arbitrarily - the main thing is that air passes through it. These can be "cheeks" parallel to the side walls of the loading hatch, or a plate on the ribs along the bottom wall.

Next, we attach a chimney from a steel pipe (it is also a residual heat exchanger) to the knee and arrange a cover. It is difficult to accurately describe the design, since most often it is performed from improvised materials. It is important to understand and implement the very principle of flow formation.

Stage three. Vertical heat exchanger system

The idea is to install a steel heat exchanger with thick walls in the path of the hot stream.

The design is an element from the second stage, increased in size, on which, instead of a vertical pipe, there will be an empty tank for dry heat exchange (ideally, an empty gas cylinder). In this case, the chimney channel must be located coaxially with the horizontal element.

The horizontal element itself (firebox) can be made in different form- stove body, pipe or box. It can serve as a pre-heat exchanger (if large enough). For long (up to 4 hours) continuous burning, it is necessary to increase the fuel compartment. It can be up to 600 mm high and take logs vertically. Combustion will occur in their lower part, and under their own weight they will burn out gradually.

Rocket furnace with heat exchanger: 1 - ash pan; 2 - cold air; 3 - fuel compartment; 4 - cover; 5 - firewood; 6 - flame boundary; 7 - combustion area; 8 - heat exchange; 9 - chimney; 10 - balloon

Primary air will be supplied through a door in the area of the firebox, which will serve as an inspection hatch for cleaning. Secondary - through a hole or channel on the knee, or through a channel in the fuel compartment.

Stage four. Installing the injector

The prototypes of secondary air supply channels were mentioned above. At this stage, we will install a separate channel for the full supply of oxygen to the flame at the stage of afterburning the fuel.

This will require a steel pipe with a diameter of 12-15 mm, curved in the form of a channel, which was obtained from the elements of the system. On the one hand, it must be drowned out and 6-8 holes 5-6 mm drilled in the wall in a section of 100 mm. Then you should install the tube in such a way that it passes through the entire system, and its “blind” end with holes is in the place where the flame reaches. The open end must exit in the "cold" part of the system and have air access. The heated metal of the tube will create thrust, and fresh air will be supplied for afterburning.

Injector installation options: 1 - ash pan; 2 - cold air; 3 - firebox; 4 - fuel compartment; 5 - injector; 6 - flame boundary; 7 - heat exchanger

Stage five. Turbocharging

An air pump is connected to the injector (possibly an old vacuum cleaner). The injector itself must have a greater throughput than with a natural supply. When the pump is turned on, the flow fresh air creates excess additional pressure, and traction increases in proportion to the applied power. This provides an increase in the temperature of the heat exchanger.

This method has been known to craftsmen since ancient times - bellows performed the function of an air pump.

When taking measures for the development of a rocket furnace, remember that the system must be harmonious - all elements must be balanced, otherwise the metal will overheat and burn out.

Do-it-yourself pyrolysis rocket oven from cans

A camping “chip” burner is always useful, especially since it does not require special materials and skills. Even a teenager can make it. However, for someone who first took up the issue of heating with "rocket" stoves, this will be a good practice, because the principle of operation is identical:

We take two tin cans of different diameters and heights (the difference is 20-25 mm).
We cut a hole equal to the diameter of the smaller jar in the bottom of the larger jar.
We make a network of holes in the bottom of the smaller jar.
We make a belt of holes on the wall of a smaller can 1/5 of its height from the open edge.
We make a belt of holes on the wall of a larger can at 1/7 of its height of the open edge.
We insert the smaller jar into the bottom of the larger one so that the bottom of the smaller one fits the open edge of the larger one. The burner is ready.

You probably already guessed that, in principle, this is a coaxial gas pipeline system. By adding various accessories to such a burner, you can increase the volume of the fuel compartment or boil water.

If you cut a hole for the channel in the wall of a larger capacity and install a fan, you get nothing more than a turbocharged RP.

Using this "pocket" option, you can conduct experiments and comparative measurements - how the material burns by itself and how with the use of secondary air.

Jet stoves have become popular not so long ago. In addition, not everyone knows about the advantages of such a heating system. It is worth noting that they are classified as energy efficient stoves. Such heating systems got their name due to reactive processes based precisely on heat transfer at significant temperature differences. At the same time, thrust arises in the jet furnace. A similar phenomenon is described in the course of basic physics. And this is thanks to the work without failures.

The design of the furnace "Rocket"

The jet furnace is always equipped with a knee, the angle of which is not more than ninety degrees. This is the main feature of this model. In other words, the chimney in relation to the bottom of the firebox is located at an acute or right angle. In this case, the oven must be equipped with an air duct. It is usually placed through the wall with the firebox.

Advantages of jet furnaces and how they work

Before a do-it-yourself jet furnace is built, it is worth understanding the principle of its operation and evaluating its merits. The main difference of such a design is that the concentration of temperature occurs precisely in the air stream, which is constantly in motion, and not in the furnace. In this case, continuous thrust occurs in the knee - in the place of heating. Air with oxygen for combustion is supplied through the duct, and in the furnace it receives a sufficient amount of thermal energy. In this case, ordinary wood can be used as fuel. In places where there is a temperature difference, it is given. Thus, traction is constantly maintained.

A jet furnace in continuous operation does not require special adjustment of the air supply. After all, the natural balance of all processes provides the necessary traction. In other words, the one that is required to maintain the desired temperature regime in the furnace. As for the exit of all exhaust gases, this process also proceeds naturally, using the pressure of already heated air. It is for this reason that the jet furnace is built with a low chimney.

The first stage of construction: flows only in their pure form

The jet furnace, the scheme of which is not so complicated, consists of several important elements. One of them is the knee. For its manufacture, two pipes can be welded at a right angle. In diameter, these parts must be at least fifteen centimeters. In this case, a ratio of 1 to 2 must be observed. As a result, a ready-made firebox with a chimney pipe should be obtained. The short part of the knee should be horizontal, and the long part vertical. If you make a fire in the pipe, then the heat will go up.

To organize the supply of secondary air, you can use one of the primitive options. To do this, a metal sheet should be installed on the brackets inside the furnace. This will move the hearth away from the duct. But the air that will pass through it will always end up in the corner of the knee. This is what makes it possible to call it secondary. To make the do-it-yourself reactive oven more functional, you can weld the legs to the finished device, and install a grate for the pan on the upper channel.

The second stage of construction: potbelly stove "rocket"

The basis is the design built at the first stage. One more important element needs to be added to it - a horizontal section. The rectangular section of the channels is much more convenient in terms of operation than pipes. A jet furnace, the drawings of which allow you to more accurately imagine the entire structure, may have a different structure. In this case, the duct can be positioned arbitrarily. However, it is worth observing one of the rules. In any case, air must pass through the duct. To do this, you can use plates on the ribs along the bottom wall, parallel side walls of the loading hatch or "brushes".

After that, the steel chimney is attached to the knee. Then you can install the roof. It is very difficult to describe exactly this structure. After all, for its manufacture usually use all sorts of improvised materials. Often a jet furnace is made from a gas cylinder. The main thing is to implement the principle of flow formation.

Third stage of construction: design with vertical heat exchanger

This idea is to create a heat exchanger made of steel with sufficiently thick walls precisely in the path of heat flows. The element built in the second stage must be increased in size. To do this, instead of a vertical pipe, an empty container must be installed, which will be used for dry heat exchange. In this case, a gas cylinder is ideal.

The jet furnace must be built in such a way that the horizontal element is aligned with the chimney channel. This moment is very important. In this case, the firebox - a horizontal element - can be made in several versions. It can be a box, a pipe or a stove body. If this part has sufficient dimensions, then it can be used as a pre-heat exchanger.

In order for the jet furnace, the scheme of which is presented above, to burn continuously for up to 4 hours, it is the fuel compartment that should be increased in size. In height, this element can be up to 60 centimeters. In this case, the loading of logs must be vertical. In such a situation, the combustion of raw materials will occur in the lower part. The logs will gradually burn and sink under their own weight.

The reactive furnace "Shirokov" is quite simple in design. Primary air is usually supplied through a door located in the area of the firebox, and secondary air is supplied through a channel or an opening on the knee.

The fourth stage of construction: installation of the injector

At this stage, it is necessary to equip the product with a separate channel, through which oxygen will flow at the stage of fuel burnout. This requires a pipe with a diameter of 1.2-1.5 centimeters, preferably curved in the shape of the channel itself, resulting from individual structural elements. On one side, a plug should be installed and up to eight holes with a diameter of six millimeters should be made in one of the walls. The area with holes made in length should be no more than 100 millimeters. The finished pipe must be installed in such a way that it passes through the entire system. In this case, the edge with the plug should reach the place where the flame still reaches. As for the open side, it should be in the cold part of the structure and have an influx of fresh air. The metal, when heated, will create the necessary traction.

Fifth stage of construction: installation of a turbocharger

Jet furnace on this stage not finished yet. Connect an air pump to the injector. For these purposes, you can use an ordinary old vacuum cleaner. In this case, the injector must have sufficient throughput. After the pump is turned on, not only will the flow of fresh air increase, but an additional one will also be created. At the same time, thrust will increase in proportion to the supplied power. This process will be provided by an increase in the temperature in the heat exchanger.

It is worth noting that this method has been known for a long time. It was used by masters. At the same time, the functions of the air pump were performed by a special blacksmith fur.

Instead of a conclusion

If you are interested in a jet stove, and you decide to install it in your house, remember a few basic rules. First of all, every detail in the system must be harmonious. Each piece of the structure must be balanced. Otherwise, overheating will occur, which will eventually lead to burn-out of metal parts. It is worth noting that it is necessary to install a jet furnace not near the wall, but at some distance from it. So it will heat the room more efficiently.

Dear visitors of the site "", today we will consider detailed instructions for self-assembly of a camping stove-rocket with your own hands without the use of welding. The jet stove appeared relatively recently and was invented abroad, but in a short period of time it gained people's love and respect in our country, especially among tourists, fishermen and hunters, and of course this stove is distinguished by its economy in consuming firewood and giving off the maximum amount of heat at the output due to jet thrust created by the furnace design itself. With its help, you can cook food in a short time, boil a kettle, which is very important in a hike.

The design of the jet furnace is very simple - it is a vertically located pipe (it is also a body and a chimney) and a firebox adjacent at an angle, divided inside by a plate into two parts (the top for loading firewood, the bottom for air access to the combustion source) thus a jet draft is formed, from here and big name « «.

The presented furnace is made with the expectation of compactness, since every gram of cargo and space in a backpack is very important on a hike. For its manufacture, a used helium cylinder was taken (a fire extinguisher can be used), its upper part was sawn off, and a technological hole for installing a firebox was cut on the side, the design is completely collapsible and all parts are in the stowed position inside the case. We remind you that during its manufacture welding machine is not needed, which simplifies the creation process to the maximum.

Let's look at all the stages of assembling a jet furnace.

materials

helium tank or used fire extinguisher
square pipe
metal perforated plate
bolts and nuts
metal sheet 1-2 mm

Instruments

Bulgarian (UShM)
drill
pliers
heat resistant paint can

Step-by-step instructions for creating a camping jet rocket furnace.

To begin with, let's look at the drawing of the domestic Robinson stove, which is also an excellent design, but welded, and the one below is much more versatile and is rightfully considered a camp stove.

First of all, you need to find a used helium cylinder or an old fire extinguisher, bleed off the remaining contents, unscrew the valve and rinse with water, then cut off the upper part, and also make a technological hole in the lower part for installing a firebox from square pipe.

We make a grate from a perforated plate.
Support legs for firebox.
We collect all the details into a single whole.

A pointed metal pin is screwed in the lower part, it is necessary so that when the furnace is installed in its working position, it stands firmly on the ground, and this stake is buried in the ground. In the stowed position, it twists. From sheet metal 1-2 mm cut out the comforter.

By the way, the pin is in the stowed position.
Also, in addition to the components from the stove, you can put a small supply of dry firewood in the cylinder, which can be very helpful in wet and rainy weather. Just imagine .. you went camping and you were caught in heavy rain, everything around you got wet, damp and disgusting, and you calmly take out your camping stove-rocket and make a fire, cook food, boil a kettle and everything is fine with you 😉
Additionally, a cable was pulled to fix the firebox.
Here is such a wonderful oven turned out, its advantage is that it is economical, compact, collapsible.

This design is made without the use of welding, which simplifies the assembly process as much as possible for those people who do not have a welding machine or do not know how to use welding. We hope our material was useful to you. You can also watch a video of the oven in action. Happy viewing!

A rocket or jet stove is a heating and cooking device that uses wood products as fuel. The popularity of such equipment is due to several factors. One of the most important is the ease of manufacture and low investment. In addition, the rocket oven is in demand because of its optimal specifications, but we'll talk about that a little later.

Several interesting features

The jet furnace appeared a long time ago. During this time, a huge number of myths have developed about such equipment. The most interesting thing is that the same operating principle is used in the rocket furnace as in the MIG-25 aircraft. Someone even said that such heating equipment works on the reverse but it's not like that at all.

All these myths and inventions are connected, rather, with the name than with the principle of operation of the device. But rocket-type stoves were only so named because they make a hissing sound, similar to that of a rocket in flight, when fired incorrectly. If the stove has been folded correctly, then it will work quietly, with a slight rustle. It can be done quickly, but not always as easy as we would like. That is why, before proceeding with the assembly, it is necessary to learn in more detail the principle of operation, characteristics, consider a couple of diagrams and drawings.

Long burning rocket stove

The main requirement put forward for jet furnaces, and for any other long-burning devices, is high heat transfer. Moreover, it is desirable that it be possible to load fuel without stopping the combustion process. If such heating equipment burns for 6-7 hours without "refueling", then it can be safely called fit.

In general, any rocket is based on the afterburning of pyrolysis gases. As you know, pyrolysis is a process of decomposition solid fuel into volatile gases, flowing under conditions of insufficient oxygen in the furnace, which slows down the combustion process and causes the fuel to smolder. All this allows a relatively small amount of wood fuel to heat the room for a long time.

Operating principle

Almost all furnaces of this type are vertically loaded. The fuel that gets into the furnace burns out, and gradually settles to the bottom. The main part of oxygen enters through the blower, due to which an excess of air is achieved, which should be enough for afterburning. But it is recommended to limit its amount, since cold streams can cool the heated mixture.

If the loading is vertical, then the main regulator is the flame, which displaces air. Usually, to maintain the pyrolysis process, that is, to maintain the temperature at the proper level, there is a flame tube. The longer it is, the better the traction. But along the entire length of the pipe, we have a significant temperature difference.

Enough important point is the heat transfer after the furnace. For more efficient heat dissipation, a small amount of(within 5-10%) is taken out. So the room heats up faster, and it becomes possible to reduce the heat loss of the riser (battery). Almost all do-it-yourself rocket furnaces are made in such a way that the riser is covered with a thin layer of metal, which will retain heat. We continue to consider the device.

Do-it-yourself rocket stove: drawings

In order for the heating equipment to work as efficiently as possible, it is necessary to be guided by the drawings during assembly. You can find them in this article and use them when assembling.

Let's talk about how to create It is needed for heating and cooking in the warm season. Heats up to 400 degrees Celsius. In this case, the oven must be portable. The firebox can be made open. The main structural difference from the classic jet furnace is that the furnace is made with a combined blower. As a result, the volumes of incoming secondary air are reduced, therefore, oxygen cannot cool the pyrolysis gas.

The hole made in the lid of the hopper allows you to adjust the temperature, although not very accurately, but it is quite enough for cooking. Now let's take a closer look at the assembly process.

First assembly step

To begin with, we need a regular canal elbow in good condition. Its dimensions may vary. It all depends on how big the oven you want to get. Two pipes (usually 150 mm in diameter) are welded at an angle of no more than 90 degrees. As a result, we get a firebox with a pipe. It must be remembered that the short section of the pipe must be horizontal, and the long one - vertical. Accordingly, the flame from the horizontal nozzle will be drawn into the vertical channel.

The most primitive way from the point of view of labor intensity to organize the supply of secondary air is that a sheet of metal is attached to the brackets in the furnace. It turns out that the hearth will be separated from the chimney. The passing air will move to the corner of the knee, which is what was required to be achieved. Please note that a do-it-yourself rocket stove (see drawings in this article) made must have legs. It is desirable to weld them. On the vertical part of the pipe, you can put a grate to cook.

The second stage: the manufacture of a rocket potbelly stove

As a basis, we take the construction obtained a little earlier. To it must be added additional element, resulting in a kind of potbelly stove. We need to make a horizontal channel. The rectangular section of the channel is more preferable, as it improves the operational properties of the unit. As for the duct, it can be made horizontal. The most important thing is that air flows through it. The most expedient solution is to install a plate with ribs along the bottom wall.

As for the chimney, it is connected to the knee. The material used is a steel pipe of suitable diameter. Often such a furnace is assembled from what is at hand. But the most important requirement is to organize a high-quality furnace and outlet. In this case, it is undesirable to use too thin metal, on which the corrosion process will be noticeable.

Furnace with vertical heat exchanger

The idea itself is quite simple to implement. It consists in the fact that a thick-walled steel heat exchanger is mounted on the path of hot streams. In this case, the construction described above is used, and an additional element is added to it. But here it is desirable to slightly increase the furnace in size and change the vertical pipe to a container for dry heat exchange. It can be an empty gas cylinder, which is ideal. True, you will have to make the chimney channel coaxially with the horizontal pipe (firebox).

The firebox can be made in various designs. The most popular are the pipe, the box and the furnace body. If the furnace is not too small, it can act as a primary heat exchanger. Therefore, if you want to achieve a long burning, say, such that the Apostle's rocket furnace has, then the fuel compartment must be expanded. Usually it is made high, about 50-60 cm. Consequently, vertically loaded logs light up from below and completely burn out under their own weight.

Mounting the injector

At the stage of afterburning the fuel, for a better process, a separate channel for supplying oxygen is installed. For this purpose, it is desirable to use steel pipe, having a diameter of not more than 18 mm, and curved. One end of the pipe must be plugged, about five or six holes of small diameter must be drilled in it. This side runs through the entire system. At the same time, the end of drilled holes must reach the flame. The free side is assigned to environment where there will be access to air. Heating the metal leads to the appearance of thrust in the tube, and oxygen is supplied for afterburning. In principle, Gabriel Apostol's rocket furnace of this type is very efficient and has a high heat dissipation.

Useful addition

If you have a desire, then at the final stage you can organize a turbocharging. To do this, you need to connect an air pump to the injector. An old vacuum cleaner or a powerful compressor will do. At the same time, pay attention to the fact that the injector has a good throughput.

The system works as follows. After turning on the pump, excess pressure is created in it. In proportion to the increase in power, traction increases. Gradually the temperature of the heat exchanger will increase. This is similar to the bellows that have been used since ancient times. Such rocket wood and other low-grade fuel will work very efficiently. Investments are practically not required, since equipment can be assembled from improvised means and materials.

The jet stove or rocket stove came about as a result of a departure from the tradition of building space heating equipment. It is considered an economical heat generator, the design of which is elementary. Therefore, many are thinking about building a jet furnace with their own hands.

Description, advantages and disadvantages of the rocket oven

A heat generator for heating the air in a room is called a rocket stove or a jet stove, because during operation, in case of excessive air intake, it makes special sounds. This noise can be mistaken for the roar of a jet engine. In normal mode, the equipment operates with a barely audible rustling sound.

The rocket stove serves as a home heating and cooking device. It takes about 6 hours to burn one batch of firewood in such equipment, more than in a standard metal stove. The reason for this is the creation of a heat generator based on a furnace with upper combustion.

The flame from the jet furnace can escape

The advantages of the rocket oven include:

independence from fuel energy;
simplicity of design, consisting of affordable parts, connected in a matter of minutes;
the ability to produce a lot of heat, despite the quality of the loaded fuel.

The jet furnace also has some disadvantages:

manual control, which implies constant monitoring of equipment operation;
danger of getting burned, because the walls of the equipment become extremely hot;
inexpediency of use in the bath, because it will not be possible to warm it up.

Kinds

A unit that emits a rocket hum during operation happens:

portable (unit of metal pipes, buckets or gas cylinder);
Portable rocket furnaces are mass-produced by the industry
stationary (created from fireclay bricks and metal containers);
Such a unit is more difficult to build than a metal furnace.
equipment for heating air with a bench.
The bed is equipped for back wall ovens

Portable structures are made in large batches, because they are used for hiking. The basis of these heat generators is a pipe made up of several segments. True, such structures, unlike units based on fireclay bricks, are not reliable. The walls of refractory blocks increase the heat transfer of the jet furnace. If desired, you can add a couch in the form of a sofa or bed, decorated with clay or sawdust.

Details and operation of a jet heat generator

An elementary rocket furnace is a device of two pipe fragments connected by a branch at an angle of 90 degrees. The combustion chamber in this heat generator is usually a zone in the horizontal part of the structure. But sometimes the fuel is placed in the vertical section of the apparatus, for which the rocket furnace is constructed from two pipes of different lengths, mounted vertically and connected by a common horizontal channel.

Primary and secondary air passes through the furnace

The functioning of the jet furnace is based on two actions: the unhindered passage of wood gases through the pipe and the afterburning of gases produced during the combustion of fuel. Wood chips and firewood are placed in the furnace of this heat generator after a highly flammable material like paper has ignited there. A container with water or other contents is placed on the open section of the pipe. At the same time, a small space is left between the structure and the installed tank, which is necessary to create traction.

The processes occurring inside a stationary jet furnace resemble the operation of pyrolysis heating units.

Calculation of parameters (tables)

The volume of the furnace should be determined with skill, because it is he who affects the power and amount of heat generated by heating equipment. When calculating the dimensions of reactive heating equipment, an indicator of the inner diameter of the drum D is used, the value of which can vary within 300–600 mm. You also need to know the area. cross section drum. To determine this indicator of a rocket furnace, use the formula: S = 3.14 * D ^ 2 / 4.

The main dimensions of the jet furnace are presented in the table:

Parameter	Meaning
Drum height H	1.5D to 2D
The height of the heat-insulating coating of the drum	2/3H
The thickness of the heat-insulating coating of the drum	1/3D
Cross-sectional area of the primary chimney	From 0.045S to 0.065S (optimally - from 0.05S to 0.06S). The higher the primary chimney, the better.
Minimum clearance between the top edge of the primary chimney and the drum cover	70 mm. With a smaller value aerodynamic drag the gap for the gases passing through it will be excessively large.
Flame tube length and area	Length and area of the primary chimney
Sectional area of the blower	Half of the cross-sectional area of the primary chimney
Cross-sectional area of the external chimney	1.5S to 2S
The thickness of the adobe pillow under the flue with a stove bench	50–70 mm (if there are wooden boards under the bed - from 25 to 35 mm)
The height of the coating above the flue with a stove bench	150 mm. It is not recommended to reduce, otherwise the oven will accumulate less heat.
Height of the external chimney	at least 4 m

Particular importance is attached to the length of the flue with a stove bench. The maximum allowable indicators are shown in the table:

The volume of the secondary ash chamber is also an important indicator, depending on the volume of the drum and the primary chimney.

D (diameter)	Volume
300 mm	0.1x (Vk - Vpd)	Where Vk is the volume of the drum, Vpd - the volume of the primary chimney.
600 mm	0.05x(Vk - Vpd)

Building materials for the construction of a non-standard furnace

The production of jet heating equipment will require the presence of:

barrels with a volume of 200 liters and a diameter of 0.6 meters, an empty cylinder from under liquefied gas or buckets of tin to build a furnace drum;
square or round pipes from steel 2-3 mm thick, which are needed to create a blower, a combustion chamber and a primary chimney;
fireclay crushed stone and furnace clay as heat-insulating materials;
adobe, which serves as an outer coating layer;
fireclay bricks;
sand from the bottom of the river;
pieces of sheets of zinc-coated steel or aluminum for the manufacture of covers and doors;
asbestos or basalt cardboard, which performs the tasks of a sealant.

Of the tools for the construction of a rocket furnace, you will need a welding machine. And if you plan to make heating equipment out of bricks, you will have to take:

Master OK;
mortar blade;
pick hammer;
stitching;
an acute-angled sledgehammer;
level;
plumb;
roulette.

Preparing for the assembly of heating equipment

When choosing a place for a rocket furnace, they are guided by some rules:

reactive heating equipment is placed only in a room with an area of at least 16 m²;
without floorboards under the oven, equipment installation will be easier;
above the structure that gives heat, it is forbidden to place wooden beams;
if it is understood that the chimney will go through the ceilings, then the heating equipment is placed in the middle of the house;
the heat generator cannot be installed near the outer contour of the house, otherwise the room will lose heated air;
the jet device must not be placed near the walls and partitions of their wooden materials.

To make it convenient to put fuel in jet heating equipment, it is more reasonable to put it front side opposite the entrance. It is important to leave at least a meter of unoccupied space around the rocket stove.

AT small house builders advise allocating a place in the corner for the stove. In this case, the firebox should be directed in one direction, and the stove bench (if it is made) in the other.

The stove stands on a special platform that protects the floor from high temperatures.

Having found a suitable site for a rocket furnace, they begin to prepare it for construction work. If boards are laid on the floor in the house, then in the place where the equipment will be installed, they will need to be removed. A hole is dug under the open floor, the bottom of which must be pressed.

Before construction works a special solution should be mixed. It consists of sand and clay combined in a ratio of 1:1. Water will be needed so much that the building materials acquire the consistency of sour cream, that is, ¼ of the amount of dry ingredients.

Do-it-yourself step-by-step instructions for making

If it is planned to make a rocket furnace from a gas cylinder, then you can not be afraid of difficulties. The steps to create equipment from such building materials are quite simple:

from a cylinder with a volume of 50 liters, the upper part is cut off in order to build a kind of cap;
The balloon is cut at the top and bottom
focusing on the instructions in the drawing, all parts of the product are welded to each other, that is, a gas cylinder, a pipe with a diameter of 10 cm (future chimney), a pipe with a diameter of 7 cm (internal channel) and another pipe with a diameter of 15 cm (firebox);
Dimensions are in mm
the space between the two pipes is filled with a material that retains heat, for example, sand, which has been carefully calcined, that is, cleaned of organic substances;
legs are welded to give stability to the structure.

To build a rocket stove with a stove bench, which involves the use of bricks, you need to act differently:

The area for arranging the firebox is deepened by removing 10 cm of soil. The combustion chamber is formed from fireclay bricks. A formwork is created along the contour of the manufactured structure. To make the base strong, it is recommended to lay a reinforcing mesh or metal bars in it;
The platform will harden in about two days
The structure is poured with liquid concrete. Then they wait for the solution to harden, and finish the job. Bricks are being laid solid line, creating a platform for the oven. After that, the walls of the structure are formed, exposing several rows of brick blocks;
They equip the lower channel of the structure, while one line of bricks is laid across to block the combustion chamber. The blocks are placed, leaving the vertical channel and the opening of the firebox open;
Two sectors of the furnace at this stage of construction must be open
They find a body from an old boiler and cut off the top and bottom covers on it. At the bottom of the resulting pipe, a flange is installed through which a horizontal heat exchanger will pass. Parts need to be connected to each other with a continuous weld;
Work requires diligence
An outlet pipe is inserted into the barrel, after which they take a brush for metal and scrape rust from the walls of the container. The cleaned barrel is treated with a primer, and a little later - with paint that is resistant to high temperatures;
The horizontal chimney is connected by welding to the side outlet - the future ash pan. To facilitate its cleaning, a sealed flange is mounted;
Spread the flame tube of refractory bricks. At the same time, a channel with a height and width of 18 cm is formed inside the structure. While doing this, they constantly use building level, which allows you to control the verticality of the product;
The height of the pipe is predetermined
The flame tube is covered with a protective casing, and the resulting gaps are clogged with perlite. The lower area of the vertical channel is sealed with wet clay, the function of which is to prevent spillage thermal insulation material on the floor;
From the boiler, on which the top and bottom were cut off, a fuel tank is formed. A handle must be welded to it;
To improve the appearance, the structure is treated with adobe putty, consisting of sawdust and raw clay. The first component of the composition serves in the same way as crushed stone in concrete, that is, it prevents cracking of the furnace walls. It is recommended to apply adobe putty on top of perlite backfill;
They create the facade of the furnace, for which the furnace circuit is laid out of stone, bricks, adobe and sand. The wrong side of the structure is filled with crushed stone, and the front side is filled with adobe mixture, which makes the surface perfectly even;
A casing made of a metal barrel is placed on the previously created base. The lower branch pipe of the tank is directed towards the bench. The bottom of the structure is treated with raw clay, which will ensure its tightness;
A channel is brought to the combustion chamber from corrugated pipe. It will serve as a link between the firebox and the atmosphere from the outside;
At this stage, the oven looks almost finished.
A test kindling of the furnace is carried out, looking at how the gases are removed from the horizontal chimney. After that, the heat exchanger pipes are connected to the lower branch pipe installed on the red brick platform;
The furnace is supplemented with a pipe for removing smoke. The junction of the chimney and the heat generator is sealed with refractory coating and asbestos cord;
Using clay and adobe, the couch is given the desired shape. Only the horizontal section of the structure is left unsealed, which will then be used during cooking.
The furnace functions as a whole system

Design improvement

A stove bench with a flue inside is not the only option for upgrading a rocket furnace. The design can be improved with a water jacket connected to heating system in which water circulates. It is desirable to give this part of the structure the appearance of a coil, created from copper pipe swirling on the chimney.

This design provides even more warmth.

Another way to improve the jet furnace is associated with the organization of the flow of heated secondary air into the flame tube. This will increase the efficiency of the heat generator, but will lead to deposits in the primary chimney a large number soot. Therefore, it is better to make sure that the drum cover can be dismantled if necessary.

The subtleties of operating an unconventional furnace

The rocket furnace is heated by analogy with the upper combustion heat generator. It turns out that the kindling of equipment called a rocket must be carried out according to certain rules:

the main raw material for the furnace of the unit should be laid only after the structure has warmed up well, for which, first, sawdust or paper is placed and set on fire in the blowing sector;
they necessarily react to the muffling of the hum coming from the furnace - they put a large batch of fuel into the combustion chamber, which will ignite on its own from the red-hot residues of sawdust;
the process is closely monitored, that is, after laying firewood, the damper is fully opened, and after a while, when the equipment makes a hum, it is covered to produce a sound similar to rustling;
as necessary, the damper is covered more and more, otherwise the furnace will become filled with an excess volume of air, which will disrupt the pyrolysis inside the flame tube and lead to the creation of a strong hum.

Since the jet oven was originally designed for field use, its design is extremely simple. This allows you to cope with the manufacture of the unit by an ordinary home master. But, despite the apparent lightness, the rocket stove is supposed to be assembled, taking into account the correct ratio of parameters. Otherwise, the equipment will be unproductive.